Fix #459 - properly support remote SPI with pigpio

Sorry! Dave's messing around with the pin implementations again.
Hopefully the last time. The pin_factory is now really a factory object
which can be asked to produce individual pins or pin-based interfaces
like SPI (which can be supported properly via pigpio).

docs/recipes.rst

@@ -9,7 +9,7 @@ library. Please note that all recipes are written assuming Python 3. Recipes
 *may* work under Python 2, but no guarantees!
 
 
-.. _pin_numbering:
+.. _pin-numbering:
 
 Pin Numbering
 =============
@@ -429,7 +429,9 @@ functionality without the need to wire up your own LEDs (also useful because
 the power and activity LEDs are "known good").
 
 Firstly you need to disable the usual triggers for the built-in LEDs. This can
-be done from the terminal with the following commands::
+be done from the terminal with the following commands:
+
+.. code-block:: console
 
     $ echo none | sudo tee /sys/class/leds/led0/trigger
     $ echo gpio | sudo tee /sys/class/leds/led1/trigger
@@ -439,7 +441,9 @@ Now you can control the LEDs with gpiozero like so:
 .. literalinclude:: examples/led_builtin.py
 
 To revert the LEDs to their usual purpose you can either reboot your Pi or
-run the following commands::
+run the following commands:
+
+.. code-block:: console
 
     $ echo mmc0 | sudo tee /sys/class/leds/led0/trigger
     $ echo input | sudo tee /sys/class/leds/led1/trigger